I have a 7mgte and plan on lapping the block, i was looking for lapping plates and realized there are many different variants. What should i look for in a lapping plate? Also, the compounds have various grit types. I am guessing through what research i have done to go with the 280 grit compound. Am i correct on this? Thanks for any help you can give me.
lapping plate and compound question
- Thread starter supramk3speed
- Start date
LOL---- I hear people talking about lapping all the time! People will say you need to lap your block if you don't take it to be machined with your head yet they will give no knowledge about what specific things to remember when lapping. Is there not specific things to know to be correct for lapping????? If anyone is knowledgable in this please let me know.
Oh well, i will just scrape the gasket residue off and use the toyota oem gasket with arp headstuds and call it a day. Cheaper that way and i plan on just making it a super reliable daily (HOPEFULLY, on the super reliable part!)
"Lapping" Is a finishing operation and should only be used AFTER the surfaces have been machined flat/true.
supramk3speed;1456440 said:
Lol i wouldnt reccomend this at all...
I had the same thought like, "Well hey im not going to beat the car
to death nor do i want to make it a power machine so ill just use a new OEM
gasket and ARP bolts to 85lbs)
75miles later.... Boom...
IJ will tell you all about it lol...
I maybe boosted twice the whole time it was running and
i didnt even open it up fully...
But seriously just do it once and do it right
super reliability that you wish to have would be with a MHG.
Its not that expensive and its worth every penny man.
Failure14;1456766 said:
WHAT?
Im on a OEM Toyota HG and ARP Headbolts torqued to 75ft lbs.
I changed it when i was swapping heads (Only the head was machined, and i cleaned up any residue off the block myself), and that was almost 10K miles ago. I boost the car daily (8-11psi)
Maybe something blew Failure14's head that he didn't think to fix. If you lean out you can blow a headgasket, so say your fuel system wasn't up to par to its original operating specs and boom. I have no idea why i blew a headgasket so im upgrading or renewing everything i can. Im going to skip this lapping and mhg thing, call me ignorant but toyota usual designs vehicles to last through astronomical abuse and these cars stock have been known to last past 60,000 miles without a headgasket failure. So i will replace the headstuds which everyone knows is the main culprit to a bhg and slap on an oem gasket and call it a day. If it blows again (before 20,000miles at least!), i kid you not i will do an engine swap.
im on felpro hg with arp's torqued to 80lb/ft and boost 15psi on my 64mm daily, for the past 3-4 months.
something else must have deff. been wrong.
something else must have deff. been wrong.
supramk3speed;1456972 said:
I appologize i should have rephrased that a little better im not saying
your headgasket wont last longer than mine and so on, cause yes
theres people that do this same thing such as kotu...
But the odds are inevitable, it will blow eventually...
Then you will have to worry about changing the rod bearings too
for the cause of rod knock.
Hope it works out though.
Failure14;1457108 said:
Well it's not "inevitable" that it's gonna blow...unless something else is wrong, as people have already said. If one isn't planning to up the boost more than a few psi (which I'm guessing is the case since the OP said he just wanted a "super reliable daily driver") then a Toyota HG is a perfect choice. Its only real weak point is detonation, but with a good tune it can hold boost as high as 15psi as kotu100 and others have shown. I mean even with the wrong factory torque specs it usually hangs in there for 60k or more...does make me curious what caused yours to blow.
if you blew a new oem headgasket something wasnt done right (including the tune). I wouldnt hesitate to use a new oem headgasket even with a bigger turbo (unless you shaved the head/block). Dr.j has said it many a times. Its in the tune.
supramk3speed;1454602 said:
Get a plate that has one sde flat, and the other side with grooves cut at a 30 to 45 degree angle. the groove side will cut faster, the flat will finish better.
Diamond paste is your best choice, but if none can be found, then emery flour mixed into lard works well. You thin that with gasoline and charge the plate with the mix, not the object being lapped.
Also, the lap plate should be made from a softer material than the item being lapped. I use a brass or soft iron for the block and lead or soft copper works well for the head.
4U2QUIK
1UZFE SWAP DUDE!!!
use clover lapping compound.
it's made by loktite, and comes in several different grits.
also 280 grit won't get you to ra20 or less. I'd suggest working up to 500 grit or better in order to get the correct finish. (I just went through this on a part for berkely space sciences lab. The part required a Ra of 9!)
it's made by loktite, and comes in several different grits.
also 280 grit won't get you to ra20 or less. I'd suggest working up to 500 grit or better in order to get the correct finish. (I just went through this on a part for berkely space sciences lab. The part required a Ra of 9!)
I have plenty of 45 Micron, and 9 Micron Diamond Paste left. PM Me an offer and it's yours!
I paid 40 bucks, and have no use!
I paid 40 bucks, and have no use!
MSC sells lots of diamond paste. Forget the carbide pastes, unless you like to work more for no purpose. You can buy a nice lapping plate from Mcmaster Carr.
None of this is cheap though, so make sure you've thought through why you need to do this.
None of this is cheap though, so make sure you've thought through why you need to do this.
^ Especially from McMaster. God knows I love the place but cheap they ain't. Their shipping is amazing though. I imagine it's even faster down there...
3p141592654;1458624 said:
:aigo: @ What McMaster Carr wants for a Lapping Plate!
Edit: OP look into the Reg Reimer Plate; i used it with great success!
http://www.supramania.com/forums/showthread.php?t=108229
jetjock;1458643 said:
Down where JJ?
Yeah, some of those plates are over the top, but they have an 8x8 for *only* $166.83! :icon_razz